Honing tool having frictionally retained honing stones



March 10, 1964 R. c. ENGLE 3,123,945

' HONING TOOL HAVING FRICTIONALLY RETAINED HONING STONES Filed Feb. 20, 1961 3 123,945 HUNING TOOL HAVING FRICTIONALLY RETAINED HUNIN G STONES Robert C. Engle, Livonia, Mich, assignor, by memo This invention relates to honing tools and particularly to a honing tool having frictionally retained honing stones therein for removing the honing stones from the tool body.

The present invention constitutes an improvement over the honing tools and honing stones disclosed in United States Patents No. 2,467,094 and No. 2,675,654. The honing stones disclosed in said patents are of the type adapted to be frictionally retained within the slots of a honing tool body, the slot being designed to tightly confine the stone on all sides thereof. While this type of honing stone has achieved wide commercial acceptance, certain difiiculties have been encountered with respect to the removal of the stones after all of the abrasive material has been expended and it is desired to replace the Worn out stones with new stones. Due to the tightness with which the stone is wedged in the slot and the relatively small amount of exposed stone area which is available to be gripped, machine operators have heretofore utilized various types of wedging tools in an attempt to pry the stone out of the tool. This is not only tedious and time-consuming, but it also produces accumulative damage to the tool which, over a period of time, can materially affect the tools performance. According to the present invention, the honing stones are provided with radially extending openings through which a simple removal tool can be inserted for extraction of the stones.

It is, therefore, an object of the present invention to provide a honing tool having frictionally supported honing stones in which the honing stones may be removed from the tool in a rapid and highly convenient manner.

It is another object of the present invention to provide a honing tool from which the stones may be removed without galling or otherwise damaging the permanent parts of the tool.

It is another object of the present invention to provide a honing tool of the above character which is inexpensive of manufacture, reliable in use and sturdy in construction.

These and other objects of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings wherein:

PEG. 1 is a fragmentary elevational view of a honing tool embodying the principles of the present invention, with a removal tool illustrated in section as being inserted in the tool;

FIG. 2 is a sectional view of the structure illustrated in FIG. 1, taken along the line 22 thereof;

FIG. 3 is a fragmentary sectional view of the structure illustrated in FIG. 2, taken along the line 33 thereof;

FIGS. 4 and 5 are front and side elevational views, respectively, of a modified form of honing stone adapted to be used with the tool shown in FIGS. 1-3;

FIG. 6 is a fragmentary front elcvational view of a honing tool embodying still another form of the present invention;

FIG. 7 is a sectional view of the structure illustrated in FIG. 6, taken along the line 7--7 thereof; and

FIG. 8 is a perspective view of a honing stone adapted to be used with the honing tool illustrated in either FIGS.

United States Patent 0 3,123,945 Patented Mar. 10, 1964 l and 2 or FIGS. 6 and 7, illustrating still another form of the present invention.

FIG. 1 shows a hollow honing tool body 10 of tubular form provided with a plurality of angularly spaced, radially open slots, one of which is illustrated at 12. Supported within each of the slots of the tool is a radially adjustable honing stone, as, for example, honing stone 14, which is disposed in slot 12 and includes an el0ngated stick of bonded abrasive material 16 encased within a surrounding shell of plastic material 18 so as to be exposed on the working face 20 thereof. A honing stone expansion member 22 is disposed within the body 10 for axial sliding movement relative thereto and is provided with a recess 24 adapted to receive the radially inner portion of the honing stone 14. An inclined cam surface 26 at the bottom of the recess 24 slidably engages an inclined rear wall 28 formed on the radially inner side of the honing stone 14. Thus, upon axial movement of the expansion member 22 relative to the body 10, the stone 14 which is held against axial movement by its confinement within the slot 12, is advanced in a radially outward direction in order to be fed against the wall of a bore or other cylindrical workpiece surface. The entire tool is, of course, intended to be rotated about and reciprocated along its longitudinal axis, which is the axis of the tubular body 19. When so operated, the thrust and torque forces produced on the stone 14 by its abrasive contact with the work surface are absorbed by the tool body 10 at the walls defining the slot 12.

The plastic material 155 of the honing stone includes a pair of radially extending, axially elongated lateral side walls 30 andn 32 on opposite sides of the abrasive stick 16 and radially extending top and bottom side walls 34 and 36 at the upper and lower ends of the stick 16. The side walls 30 frictionally engage side walls 38 and 40, respectively, of the slot 12 and top and bottom side walls 34 and 36 engage arcuately shaped upper and lower walls 42 and 44, respectively, of the slot 12. The side wall 30 is shown as having a radially extending recess or groove 46 formed in the exposed face thereof so as to define a radially extending opening bounded by the bottom of said groove 46 and the confronting portion 48 of the slot side wall 38. The groove 46 communicates with an enlarged recess 50 at the radially inner edge of the stone, which provides, a shoulder 52 intersecting the wall of the groove 46.

The foregoing stone construction permits the use of a removal tool, indicated at 54 as having a handle 56, a shank 53 and a prong 6t) at the free end of the shank which is disposed at a right angle to the length of the shank 58. The shank of the tool 54 is inserted into the groove with the prong aligned in an axial direction. When the prong 60 has reached the opening of the recess 50, the tool 54 is rotated 90 degrees and the prong 6% is brought into contact with the shoulder 52. By the application of a radially outward manual force to the handle 56, the entire stone 14 may thereby be pulled out of the slot 12. Thus, the stone may be removed from the tool in an efiicient, rapid manner without prying, wedging, or other activity which might damage the tool body 10 or the expansion member 22.

FIGS. 4 and 5 illustrate another form of honing stone 64 having an abrasive stick 66 encased within a plastic shell 68. In this embodiment, a groove 70 is formed in a side wall 72 which is at the upper end of the stone and is axially spaced from the length of the stick 66. The groove 70 communicates with a recess 74 having a shoulder 76 which may be contacted by the tool prong 60 for removal of the stone in the manner previously described for the removal of the stone 14.

FIGS. 6 and 7 disclose a form of the invention in which a honing tool body 78 is provided with a slot 80 having a spring retainer 82 inserted therein. The retainer 82 and its spring arm 84 encircle and engage a honing stone 86 which is supported within the slot 80 for sliding radial feed movement. The honing stone includes a bonded abrasive stick 88 set within a plastic shell 90, so that the working face 92 thereof is exposed and faces in a radially outward direction. The plastic shell includes opposite side wall portions 94 and 96 on opposite lateral sides of the stone 86 and top and bottom side wall portions 98 and 100 at the top and bottom of the abrasive stick 88. The details of construction, as well as the function and operation of the retainer 82 are more fully described in my co-pending application, Serial No. 90,385, filed February 20, 1961. The retainer provides a continuous side wall which engages each of the stone side walls 94, 96, 98 and 100 and, as used in the appended claims, the expression slot side Wall is intended to include the material of the retainer 82 which lies along and engages the side walls which define the slots per se.

It will be seen that the side wall 98 is provided with a radially extending groove 102 at the periphery thereof which extends the entire depth of the stone from the top thereof to the radially inner margin of the stone at a shoulder 104 formed by the radially inner or inclined rear Wall of the stone. It will be seen that the shoulder 104 is adapted to be engaged by the cam surface 105 of a cone expansion member 106 disposed within the body 78 for radial feed movement of the stone 86 upon axial movement of the stone expansion member 106 relative to the body 78. When the abrasive material 88 of the stone has been consumed and it is desired to remove the remaining portion of the stone 86 before insertion of a new stone, the expansion member 106 is first retracted or moved in an axially upward direction to the position shown in FIG. 7. This moves cam surface 105 out of contact with the shoulder 104 and provides a space inwardly of the shoulder 104, whereby the projection 60 on the shank 58 of the tool 54 may be moved through the opening 102 into engagement with the shoulder 104. Thus, the application of a radially outward pulling force on the handle 56 of the tool 54 will pull the stone 86 out of the tool body.

It will be seen that this embodiment of the invention differs from the prior embodiments in that retraction of the honing stone expansion element 106 is required in order to permit complete insertion of the tool 54 into engagement with a suitable radially inwardly facing shoulder for extraction of the stone.

FIG. 8 illustrates a modified honing stone 107 having a central bonded abrasive stick 108 encased within a plastic shell 110 having a lateral side wall 112 provided with a radially extending slot or groove 114 extending from the face of the stone to the rear wall or shoulder 116 thereof. The stone 106 differs from the stone 86 only in the location of the groove 114, the groove being located in a lateral side wall, rather than in a top side wall.

While it will be apparent that the preferred embodiments herein illustrated are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. A rotary honing tool including a hollow body member having a radially open slot, 21 honing stone press fit in said slot and having a length of abrasive material and a shell of non-abrasive material supporting said abrasive material and provided with a wall portion on one side of said abrasive material, said wall portion being confined against a wall of said slot for sliding radial movement therealong and having a radially extending groove confronting said slot wall to define a radially extending open ing, said honing stone having a radially inwardly facing surface adjacent said opening engageable by a tool inserted through said opening to remove said honing stone from said slot in a radially outward direction.

2. A rotary honing tool including a hollow body member having a radially open slot, a honing stone press fit in said slot having a length of abrasive material and a shell of non-abrasive material supporting said abrasive material and provided with a wall portion on one side of said abrasive material and a radially inwardly facing surface inclined with respect to the axis of rotation and a honing stone expansion member engaging said inclined surface, said non-abrasive honing stone material having an opening extending radially through said wall portion and a recess adjacent said opening, said recess being provided with a shoulder engageable by a tool inserted through said opening to remove said honing stone from said slot in a radially outward direction.

3. A rotary honing tool including a hollow body mem ber having a radially open slot, a honing stone press fit in said slot having a length of abrasive material, and a supporting shell of non-abrasive material provided with a wall portion on one side of said abrasive material and a surface on the radially inner side thereof inclined with respect to the axis of rotation of the tool, a honing stone expansion member disposed within said hollow body member and engageable with the inclined surface of said honing stone for radially advancing said honing stone upon axial movement thereof, said honing stone wall portion being frictionally and slidably engageable with a wall of said slot and having a radially extending groove therein confronting said slot wall to define an opening extending radially inwardly from the radially outer face of said honing stone and said non-abrasive material having a recess therein adjacent said inclined surface provided with a shoulder engageable by a tool inserted through said opening to remove said honing stone from said slot in a radially outward direction.

4. A rotary honing tool including a hollow body member having a radially open slot, a honing stone press fit in said slot having a length of abrasive material, and a supporting shell of non-abrasive material provided with a Wall portion on one side of said abrasive material and a surface on the radially inner side thereof inclined with respect to the axis of rotation of the tool, a honing stone expansion member disposed within said hollow body member and engageable with the inclined surface of said honing stone for radially advancing said honing stone upon axial movement thereof, said honing stone wall portion being frictionally and slidably engageable with a wall of said slot and having a radially extending groove therein confrontnig said slot wall to define an opening extending from the radially outer face of said honing stone to said inclined surface, whereby said honing stone may be removed from said slot by the retraction of said honing stone expansion member away from said inclined surface and the insertion of a tool through said opening for the application of a radially outward pulling force to said inclined surface.

References Cited in the file of this patent UNITED STATES PATENTS 1,886,584 Prange Nov. 8, 1932 2,305,076 Graham Dec. 15, 1942 2,675,654 Harris Apr. 20, 1954 

1. A ROTARY HONING TOOL INCLUDING A HOLLOW BODY MEMBER HAVING A RADIALLY OPEN SLOT, A HONING STONE PRESS FIT IN SAID SLOT AND HAVING A LENGTH OF ABRASIVE MATERIAL AND A SHELL OF NON-ABRASIVE MATERIAL SUPPORTING SAID ABRASIVE MATERIAL AND PROVIDED WITH A WALL PORTION ON ONE SIDE OF SAID ABRASIVE MATERIAL, SAID WALL PORTION BEING CONFINED AGAINST A WALL OF SAID SLOT FOR SLIDING RADIAL MOVEMENT THEREALONG AND HAVING A RADIALLY EXTENDING GROOVE CONFRONTING SAID SLOT WALL TO DEFINE A RADIALLY EXTENDING OPENING, SAID HONING STONE HAVING A RADIALLY INWARDLY FACING SURFACE ADJACENT SAID OPENING ENGAGEABLE BY A TOOL INSERTED THROUGH SAID OPENING TO REMOVE SAID HONING STONE FROM SAID SLOT IN A RADIALLY OUTWARD DIRECTION. 